CN111610173B - Three-dimensional fluid concentration field calibration device and calibration method - Google Patents
Three-dimensional fluid concentration field calibration device and calibration method Download PDFInfo
- Publication number
- CN111610173B CN111610173B CN202010460551.1A CN202010460551A CN111610173B CN 111610173 B CN111610173 B CN 111610173B CN 202010460551 A CN202010460551 A CN 202010460551A CN 111610173 B CN111610173 B CN 111610173B
- Authority
- CN
- China
- Prior art keywords
- calibration
- layer cavity
- cavity
- layer
- sub
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
- G01N21/64—Fluorescence; Phosphorescence
- G01N21/6402—Atomic fluorescence; Laser induced fluorescence
Abstract
The application relates to a three-dimensional fluid concentration field calibration device and a calibration method. The three-dimensional fluid concentration field calibration device is provided with the two first partition plates and the at least two second partition plates in the calibration box body, so that a containing cavity formed by surrounding the calibration box body can be divided into a first layer cavity, a second layer cavity and a third layer cavity, and meanwhile, the second layer cavity is divided into at least three sub-cavities. In the actual measurement process, liquid outside the calibration device enters the first layer cavity, the second layer cavity, the third layer cavity and the sub-cavity through the liquid inlet hole, fluorescent substance solution with preset concentration is configured in the first layer cavity, the second layer cavity, the third layer cavity and the sub-cavity, planar laser scans along the distribution direction of the first layer cavity, the second layer cavity and the third layer cavity of the calibration device, multi-frame fluorescence scanning images of different positions of the calibration device can be obtained, the calibration coefficient of a three-dimensional fluid concentration field can be obtained according to the scanning images, the calibration process is completed, and the measurement precision of the 3 IF DLequipment is improved.
Description
Technical Field
The application relates to the technical field of flow measurement, in particular to a three-dimensional fluid concentration field calibration device and a calibration method.
Background
In three-dimensional Laser Induced Fluorescence (3D DLIF) measurement, on-site calibration and correction are usually required to accurately invert the image gray-scale distribution into a true three-dimensional concentration field.
In a traditional Planar Laser Induced Fluorescence (PLIF) calibration method, uniform concentration fields with different concentrations are usually constructed for measurement, image gray scale is extracted, and a correlation relation between the image gray scale and the concentration is constructed, so that correction of on-way attenuation of a sheet light source is realized. However, the PLIF calibration method cannot achieve calibration in the 3DLIF measurement process.
Disclosure of Invention
Therefore, it is necessary to provide a three-dimensional fluid concentration field calibration device and a calibration method for solving the problem that the PLIF calibration method cannot realize calibration in the 3DLIF measurement process.
The application provides a three-dimensional fluid concentration field calibration device, includes:
the calibration box body is surrounded to form an accommodating cavity;
the two first partition plates are arranged in the accommodating cavity and used for dividing the accommodating cavity into a first layer cavity, a second layer cavity and a third layer cavity along the length or width direction of the calibration box body;
the second layer cavity is divided into at least three sub-cavities along a direction perpendicular to the distribution direction of the first layer cavity, the second layer cavity and the third layer cavity; and
the calibration box body is provided with a liquid inlet hole, liquid outside the calibration box body enters the first layer cavity, the second layer cavity, the third layer cavity and the sub-cavity through the liquid inlet hole, the first layer cavity, the second layer cavity, the third layer cavity and the sub-cavity are used for configuring fluorescent substance solution with preset concentration, and the calibration box body, the first partition plate and the second partition plate are made of light-transmitting materials.
In one embodiment, the first layer cavity and the third layer cavity have the same volume, and the lengths of the first layer cavity and the third layer cavity along the distribution direction of the first layer cavity, the second layer cavity and the third layer cavity are the same.
In one embodiment, the volumes of at least three sub-cavities are the same, and the lengths of at least three sub-cavities along the direction perpendicular to the distribution direction of the first layer cavity, the second layer cavity and the third layer cavity are the same.
Based on the same inventive concept, the application also provides a three-dimensional fluid concentration field calibration method, which comprises the following steps:
installing a calibration device and opening a liquid inlet hole of the calibration device until the inner liquid level of the calibration device is flush with the outer liquid level;
adjusting the positions of the calibration device and the detection device so that the incident plane laser is perpendicular to the distribution direction of a first layer cavity, a second layer cavity and a third layer cavity in the calibration device, and is incident into the calibration device along the height direction of the calibration device, and the detection plane of the detection device is perpendicular to the distribution direction of the first layer cavity, the second layer cavity and the third layer cavity;
preparing the fluorescent substance solution of each cavity in the calibration device according to the preset concentration of the fluorescent substance solution of each cavity in the calibration device and uniformly stirring;
scanning the planar laser along the distribution direction of the first layer cavity, the second layer cavity and the third layer cavity, and acquiring a multi-frame scanning image by using the detection device while scanning, wherein the planar laser and the detection device move synchronously;
and determining a three-dimensional fluid concentration field calibration coefficient according to the multi-frame scanning image and calibrating.
Based on the same inventive concept, the application also provides a three-dimensional fluid concentration field calibration method, which comprises the following steps:
determining the positions of a first layer cavity, a second layer cavity and a third layer cavity in a calibration device according to a multi-frame scanning image of the calibration device;
determining the positions of at least three sub-cavities in the second layer of cavity according to the scanning image of the second layer of cavity;
determining a first calibration coefficient and a second calibration coefficient according to the average gray value of the positions of at least three sub-cavities and the corresponding preset concentration of the fluorescent substance solution, wherein the first calibration coefficient is the ratio of the fluorescent concentration to the image gray value, and the second calibration coefficient is the initial threshold of the image gray value;
determining a third calibration coefficient according to the image gray scale of the position of the sub cavity with the maximum preset concentration of the fluorescent substance solution in the at least three sub cavities, wherein the third calibration coefficient is the on-way attenuation characteristic of the laser;
determining a fourth calibration coefficient and a fifth calibration coefficient according to the scanned image of the first layer cavity and the scanned image of the third layer cavity, wherein the fourth calibration coefficient is the fluorescence absorption characteristic of the fluorescent substance solution, and the fifth calibration coefficient is the fluorescence attenuation characteristic in water;
and converting the scanning image in the measuring process into concentration distribution according to the first calibration coefficient, the second calibration coefficient, the third calibration coefficient, the fourth calibration coefficient and the fifth calibration coefficient so as to realize calibration of the three-dimensional fluid concentration field.
In one embodiment, the method further comprises the following steps:
after the positions of at least three sub cavities in the second layer of cavity are determined according to the scanning image of the second layer of cavity, the posture, the moving direction and the moving speed of a detection device are adjusted according to the scanning image of the first layer of cavity and the scanning image of the second layer of cavity;
and correcting the multi-frame scanning image of the calibration device according to the scanning image of the first layer cavity.
In one embodiment, adjusting the posture, the moving direction and the moving speed of the detecting device according to the scanned image of the first layer cavity and the scanned image of the second layer cavity comprises:
performing edge recognition on the scanned image of the first layer cavity, and extracting an effective area of the scanned image of the first layer cavity;
calculating a scanning image scale according to the pixel spacing of the detection device and the size of the calibration device;
adjusting the posture of the detection device according to the effective area and the scanning image scale;
carrying out convolution cross-correlation processing on the scanned images of the plurality of second-layer cavities to obtain scale variation and image drift;
and adjusting the moving direction and the moving speed of the detection device according to the scale variation and the image drift amount so as to realize the adjustment of the scanning image shift direction and the scan image shift speed acquired by the detection device.
In one embodiment, the correcting the multi-frame scanning image of the calibration device according to the scanning image of the first-layer cavity includes:
determining a dimensionless gray value distribution function according to the scanning image of the first layer cavity;
and correcting the multi-frame scanning image of the calibration device by adopting the dimensionless gray value distribution function.
In one embodiment, the determining a first calibration coefficient and a second calibration coefficient according to the average gray-scale value at the positions of at least three sub-cavities and the corresponding preset concentration of the phosphor solution includes:
fitting the average gray value of the positions of at least three sub cavities with the corresponding preset concentration of the fluorescent substance solution in the form of
Wherein
Is the average gray value at the position of the sub-cavity,
is a preset concentration of the phosphor solution,
in order to obtain the first calibration coefficient,
and the second calibration coefficient.
In one embodiment, the determining a third calibration coefficient according to the image gray scale at the position of the sub-cavity with the maximum preset concentration of the phosphor solution in the at least three sub-cavities includes:
fitting the average gray value of each line at the position of the sub cavity with the highest preset concentration of the fluorescent substance solution in the form of
Then the third calibration coefficient is
，
Is the maximum value of the preset concentration of the phosphor solution.
In one embodiment, the determining a fourth calibration coefficient and a fifth calibration coefficient according to the scanned image of the first layer cavity and the scanned image of the third layer cavity includes:
dividing the scanning image of the first layer cavity into a plurality of first areas, dividing the scanning image of the third layer cavity into a plurality of second areas, wherein the first areas and the second areas are in one-to-one correspondence, and the number and the positions of the first areas and the second areas are the same as those of the sub-cavities;
and calculating the ratio of the average gray value of each first region to the average gray value of the corresponding second region, and determining the fourth calibration coefficient and the fifth calibration coefficient according to the ratio.
In one embodiment, the calculating a ratio between the average gray-scale value of each first region and the average gray-scale value of the corresponding second region, and determining the fourth calibration coefficient and the fifth calibration coefficient according to the ratio includes:
fitting the ratio of the average gray value of the first region to the average gray value of the second region in the form of
Wherein
Is the ratio of the average gray-scale value of the first region to the corresponding average gray-scale value of the second region,
the fourth calibration factor is the preset concentration of the phosphor solution
Wherein
The second layer cavity is arranged along the first layer cavity, the second layer cavity and theThe length of the third layer cavity in the distribution direction, and the fifth calibration coefficient is
Wherein
Is the spacing between the first region and the second region.
The application provides a three-dimensional fluid concentration field calibration device through set up two first baffles and two at least second baffles in maring the box, can surround the chamber that holds that forms and divide into first layer cavity, second floor cavity and third layer cavity with maring the box, divides the second floor cavity into at least three subcavities simultaneously. In the actual measurement process, the water body to be measured outside the calibration device can enter the first layer cavity through the liquid inlet hole, the second layer cavity, the third layer cavity and the sub-cavity, the first layer cavity, the second layer cavity, the third layer cavity and the sub-cavity can be used for configuring fluorescent substance solution with preset concentration, the planar laser scans along the distribution direction of the first layer cavity, the second layer cavity and the third layer cavity of the calibration device, multi-frame fluorescence scanning images of different positions of the calibration device can be obtained, the calibration coefficient of the three-dimensional fluid concentration field can be obtained according to the scanning images, therefore, the calibration of the three-dimensional fluid concentration field is completed, and the measurement precision of the 3DLIF equipment is improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic three-dimensional structure diagram of a three-dimensional fluid concentration field calibration apparatus according to an embodiment of the present disclosure;
fig. 2 is a schematic structural diagram of a three-dimensional fluid concentration field calibration system according to an embodiment of the present disclosure;
fig. 3 is a flowchart of a three-dimensional fluid concentration field calibration method according to an embodiment of the present disclosure;
fig. 4 is a flowchart of a three-dimensional fluid concentration field calibration method according to an embodiment of the present disclosure and a result diagram;
FIG. 5 is a flow chart of another three-dimensional fluid concentration field calibration method provided by an embodiment of the present application;
fig. 6 is a schematic diagram illustrating a top view structure and concentrations of cavities of a three-dimensional fluid concentration field calibration apparatus according to an embodiment of the present disclosure;
fig. 7 is a schematic diagram of a width of a cavity of a second layer and a distance between two characteristic cross sections in a three-dimensional fluid concentration field calibration method according to an embodiment of the present application.
Description of the reference numerals
100 calibration device
10 demarcate box
110 holding cavity
111 first layer cavity
112 second layer cavity
113 third layer cavity
114 subcavity
120 liquid inlet hole
20 first partition plate
30 second partition plate
200 detection device
Detailed Description
In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and those skilled in the art will be able to make similar modifications without departing from the spirit of the application and it is therefore not intended to be limited to the embodiments disclosed below.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
In Laser Induced Fluorescence (LIF) measurement, the Fluorescence intensity emitted by a single fluid infinitesimal satisfies the requirement
. Wherein the content of the first and second substances,
in order to irradiate the intensity of the laser light in this region,
is the light absorption coefficient of the fluorescent substance,
in order to obtain the quantum yield of the fluorescent substance,
the concentration of the fluorescent substance in the region is,
is the fluid infinitesimal volume. According to the principle of concentration field measurement,
and
is a relatively constant coefficient of fluorescence emitted by the fluid infinitesimalStrength of
Intensity of laser beam
Is in direct proportion, if
The intensity of the fluorescence obtained is measured while remaining constant
Concentration of the reactive fluid
I.e. laser intensity
The amplitude of the change in (b) affects the fluorescence intensity
The measurement accuracy of (2). Therefore, in order to obtain accurate information of fluorescence intensity in a certain section, it is necessary to use a laser sheet light source for fluorescence excitation, and the higher the intensity of the laser sheet light source is, the higher the fluorescence intensity is
The larger the sensitivity of the system.
It will be appreciated that LIF techniques require field calibration. If the field calibration process is not available, the LIF technology can only carry out qualitative measurement, and the measured three-dimensional concentration field is only a relative value and has larger error. And the field calibration can acquire the water quality influence and the light source state in the actual measurement process, thereby ensuring higher measurement precision when the concentration field is quantitatively measured. It should be noted that, the calibration in this application refers to converting the gray scale information of the scanned image into the density information, and correcting the error existing in the measurement process by a specific algorithm, so as to improve the measurement accuracy of the three-dimensional density field. Therefore, the field calibration can obtain a plurality of calibration parameters representing different physical properties and laser intensity distribution under actual measurement conditions, and the calibration parameters and the laser intensity distribution can be used in the data processing process of the scanned image, so that the scanned image sequence obtained in the actual measurement is accurately converted into a three-dimensional concentration field.
Referring to fig. 1, the present application provides a three-dimensional fluid concentration field calibration apparatus 100. The calibration apparatus 100 includes a calibration housing 10, two first partitions 20, and at least two second partitions 30. The calibration housing 10 encloses a receiving chamber 110. The two first partition boards 20 are disposed in the accommodating cavity 110, and are used for dividing the accommodating cavity 110 into a first-layer cavity 111, a second-layer cavity 112, and a third-layer cavity 113 along the length or width direction of the calibration box 10. The at least two second partition boards 30 are disposed in the second-layer cavity 112, and are used for dividing the second-layer cavity 112 into at least three sub-cavities 114 along a direction perpendicular to the distribution direction of the first-layer cavity 111, the second-layer cavity 112, and the third-layer cavity 113. The calibration box 10 is provided with a liquid inlet 120, liquid outside the calibration box 10 enters the first layer cavity 111, the second layer cavity 112, the third layer cavity 113 and the sub-cavity 114 through the liquid inlet 120, the first layer cavity 111, the second layer cavity 112, the third layer cavity 113 and the sub-cavity 114 are used for configuring a fluorescent solution with a preset concentration, and the calibration box 10, the first partition plate 20 and the second partition plate 30 are made of light-transmitting materials.
It can be understood that the calibration device 100 provided by the present application can accurately obtain the conditions that the three-dimensional concentration field is affected by the field measurement conditions, such as the conditions of the device installation error, the influence of the water quality to be measured on the fluorescence absorption coefficient and the quantum yield, the influence of the water body on the fluorescence absorption effect, the laser distribution, and the like, before the 3DLIF measurement is performed. In this embodiment, the calibration box 10 may be a uncovered square casing, that is, the square casing only includes four side walls and a bottom wall, the first partition plate 20 and the second partition plate 30 are installed inside the accommodating cavity 110 formed by the calibration box 10, wherein the calibration box 10, the first partition plate 20 and the second partition plate 30 may all be made of high-transmittance acrylic material, or may also be made of other materials having a transmittance of more than 98%. It can be understood that the high-transmittance acrylic material and the material with the light transmittance exceeding 98% are beneficial to the incidence of the planar laser and the acquisition of the fluorescence scanning image, so that the accuracy of the calibration coefficient obtained by using the calibration device 100 is improved.
It is understood that the first partition 20 may divide the accommodating cavity 110 formed by the calibration box 10 into three layers, i.e. a first layer cavity 111, a second layer cavity 112 and a third layer cavity 113. In this embodiment, the first partition 20 may be parallel to the front surface of the calibration box 10 and has the same area as the front surface of the calibration box 10, wherein the front surface of the calibration box 10 may be a plane where the length of the square housing is located. In one embodiment, the volumes of the first layer cavity 111 and the third layer cavity 113 are the same, and the lengths of the first layer cavity 111 and the third layer cavity 113 along the distribution direction of the first layer cavity 111, the second layer cavity 112 and the third layer cavity 113 are the same. It can be understood that the first layer cavity 111 and the third layer cavity 113 have the same volume, which is convenient for calculation of the fluorescent substance mother liquor when the calibration device 100 is used, the lengths of the first layer cavity 111 and the third layer cavity 113 along the distribution direction (the length or width direction of the square shell) of the first layer cavity 111, the second layer cavity 112, and the third layer cavity 113 are the same, and the positions of the first layer cavity 111 and the third layer cavity 113 do not need to be distinguished, so that the flexibility of the calibration device 100 when placed is improved.
It is to be understood that the second baffle 30 may divide the second layer cavity 112 into at least three sub-cavities 114. The second partition 30 may be parallel to the side of the second-layer cavity 112 and have the same area as the side of the second-layer cavity 112, wherein the side of the second-layer cavity 112 may be located on the plane where the width and the height of the calibration box 10 (square housing) are located. In one embodiment, the volumes of the at least three sub-cavities 114 are the same, and the lengths of the at least three sub-cavities 114 along the direction perpendicular to the distribution direction of the first layer cavity 111, the second layer cavity 112 and the third layer cavity 113 are the same. It can be understood that the volumes of the at least three sub-cavities 114 are the same, and the lengths of the sub-cavities in the direction perpendicular to the distribution direction of the first layer cavity 111, the second layer cavity 112, and the third layer cavity 113 are the same, so that the calculation process of the fluorescence mother liquor and the subsequent image processing process can be simplified, that is, the use process of the calibration device 100 is simplified, and the application range of the calibration device 100 is expanded. Of course, the volumes of the at least three sub-cavities 114 and the lengths along the direction perpendicular to the distribution direction of the first layer cavity 111, the second layer cavity 112 and the third layer cavity 113 may also be different, and this is not particularly limited in this application. In one embodiment, the second layer cavity 112 may include five sub-cavities 114, and the lengths of the five sub-cavities 114 are the same in a direction perpendicular to the distribution direction of the first layer cavity 111, the second layer cavity 112, and the third layer cavity 113.
It is understood that the first layer chamber 111, the second layer chamber 112, the third layer chamber 113 and the sub-chamber 114 are used to configure a solution of the fluorescent substance with a predetermined concentration. The concentration of the phosphor solution in the first layer cavity 111, the second layer cavity 112, the third layer cavity 113 and the sub-cavity 114 is not limited in the present application as long as it can meet the requirement of calibration parameter measurement. In one embodiment, the phosphor solutions with the same concentration may be disposed in the first layer cavity 111 and the third layer cavity 113, and the phosphor solutions with different concentrations may be disposed in the sub-cavities 114 in the second layer cavity 112, where it is to be noted that the phosphor solutions in the sub-cavities 114 in the second layer cavity 112 cannot be completely the same, and the setting is specifically required according to the number of the sub-cavities 114 and a subsequent image processing method.
In addition, the sidewall of the calibration box 10 and the second partition 30 in the second-layer cavity 112 are both provided with liquid inlet holes 120, and at the same time, plugs matched with the liquid inlet holes 120 can be configured. In one embodiment, the plug matched with the liquid inlet 120 may be a rubber plug, and the liquid inlet 120 needs to ensure that the water to be measured outside the calibration device 100 can enter each cavity of the calibration device 100. A plurality of mounting holes have been seted up at the four corners of calibration device 100's diapire, and the mounting hole can be for running through the screw, can be used for fixed calibration device 100, avoids taking place to remove calibration device 100 in calibration coefficient survey process, improves calibration device 100 measuring accuracy. It is understood that the size of the calibration apparatus 100 is not particularly limited in the present application, and may be actually selected according to the measurement range of the 3DLIF measurement device and the installation condition of the area to be measured.
The three-dimensional fluid concentration field calibration device 100 provided by the application can divide an accommodating cavity 110 formed by surrounding the calibration box 10 into a first layer cavity 111, a second layer cavity 112 and a third layer cavity 113 by arranging two first partition plates 20 and at least two second partition plates 30 in the calibration box 10, and divide the second layer cavity 112 into at least three sub-cavities 114. In the actual measurement process, a water body to be measured outside the calibration device 100 can enter the first layer cavity 111, the second layer cavity 112, the third layer cavity 113 and the sub-cavity 114 through the liquid inlet hole 120, and fluorescent substance solutions with preset concentrations are configured in the first layer cavity 111, the second layer cavity 112, the third layer cavity 113 and the sub-cavity 114, the planar laser scans along the distribution direction of the first layer cavity 111, the second layer cavity 112 and the third layer cavity 113 of the calibration device 100, so that multi-frame fluorescent scanning images of different positions of the calibration device 100 can be obtained, calibration coefficients of a three-dimensional fluid concentration field can be obtained according to the scanning images, calibration of the three-dimensional fluid concentration field is completed, and the measurement accuracy of the 3DLIF device is improved.
Referring to fig. 2 to 4, based on the same inventive concept, the present application further provides a three-dimensional fluid concentration field calibration method, including:
step S10, installing the calibration device 100 and opening the liquid inlet hole 120 of the calibration device 100 until the inner liquid level of the calibration device 100 is flush with the outer liquid level;
step S20, adjusting the positions of the calibration device 100 and the detection device 200, so that the incident plane laser is perpendicular to the distribution direction of the first layer cavity 111, the second layer cavity 112, and the third layer cavity 113 in the calibration device 100, and is incident into the calibration device 100 along the height direction of the calibration device 100, and the detection plane of the detection device 200 is perpendicular to the distribution direction of the first layer cavity 111, the second layer cavity 112, and the third layer cavity 113;
step S30, preparing and uniformly stirring the fluorescent substance solution of each cavity in the calibration device 100 according to the preset concentration of the fluorescent substance solution of each cavity in the calibration device 100;
step S40, scanning the first layer cavity 111, the second layer cavity 112 and the third layer cavity 113 by using plane laser along the distribution direction, and acquiring multi-frame scanning images by using the detection device 200 while scanning, wherein the plane laser and the detection device 200 move synchronously;
and step S50, determining a three-dimensional fluid concentration field calibration coefficient according to the multi-frame scanning image and performing calibration.
In the embodiment, a 3d if device is used to measure the concentration field of the water in the water tank, and the calibration device 100 is used to perform calibration before the measurement of the concentration field. In step S10, the calibration device 100 needs to be installed on site for different water bodies to be measured, that is, after the liquid inlet 120 of the calibration device 100 is opened, the calibration device 100 is placed in the water tank in which the water body to be measured is located. According to the principle of the communicating vessel, the liquid level in the calibration device 100 will gradually rise to the measurement water level, and the liquid inlet hole 120 can be blocked after the liquid level in the calibration device 100 is flush with the liquid level outside. In the successful process, the water body calibration area and the water body area to be measured can be completely superposed, namely the images of the inner liquid surface and the outer liquid surface are superposed, so that the interference of the reflected light of the free liquid surfaces of multiple water bodies on the scanned image is eliminated, and the calibration precision of the three-dimensional fluid concentration field calibration method is improved.
In step S20, the positions of the calibration device 100 and the detection device 200 are adjusted such that the front surface of the calibration device 100 may be parallel to the incident planar laser, and the planar laser may be incident from the bottom wall of the calibration device 100 along the height direction, wherein the front surface of the calibration device 100 may be the plane where the length of the calibration box 10 is located. Meanwhile, the front surface of the calibration device 100 faces the detection plane (or the photographing lens) of the detection device 200, and at this time, the calibration area completely coincides with the water body area to be detected. In this embodiment, a scanning image of the multi-frame calibration apparatus 100 is obtained according to the synchronous scanning of the calibration apparatus 100 and the detection apparatus 200, and a calibration coefficient of the three-dimensional fluid concentration field can be extracted to complete the calibration of the three-dimensional fluid concentration field.
In step S30, the maximum concentration that may occur in the measured region when the concentration field measurement experiment is performed, for example, 0.02ppm, may be estimated first. The water depth in the calibration device 100 is measured and the volume of the liquid in the calibration device 100 is calculated from the dimensions of the cavities of the calibration device 100. Calculating the volume of the fluorescence mother liquor needed to be used by each cavity of the calibration device 100 according to the estimated maximum concentration and the fluorescence mother liquor concentration, adding the corresponding fluorescence mother liquor into each cavity, and uniformly stirring to complete the configuration of the fluorescence solution of each cavity in the calibration device 100.
In step S40, the 3DLIF measurement device is activated, and the 3DLIF measurement device may emit planar laser light and scan the planar laser light along the distribution direction of the first layer cavity 111, the second layer cavity 112, and the third layer cavity 113. The emergent planar laser can perform multiple (or single) reciprocating scanning, and the detection device 200 can obtain different planar fluorescence images, i.e. multi-frame scanning images, of the calibration device 100 by synchronously moving relative to the planar laser. It should be noted that, in the scanning process, it is required to ensure that the detecting device 200 (camera), the reflecting mirror, the compensating mirror and other devices also perform synchronous motion at a fixed speed, so that the influence caused by the change of the laser optical path and the shooting distance in the scanned image can be eliminated, and the calibration accuracy of the three-dimensional fluid concentration field calibration method is improved.
In step S50, by performing image processing on the multi-frame scan image of the calibration apparatus 100, a plurality of calibration coefficients of the three-dimensional fluid concentration field can be determined, and the three-dimensional fluid concentration field is calibrated according to the calibration coefficients, so that the measurement accuracy of the three-dimensional fluid concentration field can be improved. In one embodiment, the measured calibration coefficients may be output as a field calibration file in a specific format and loaded into computer software for actual measurement.
In one embodiment, the square cross section of the water tank in which the water body to be measured is located may be 0.4m (width) × 0.6 (height) m, the length of the experimental section is 1.5m, and the water level of the experiment is 0.45m, where the experimental section is a portion of the circulating water tank where optical measurement can be performed. In this embodiment, the measurement area of the 3DLIF device is 0.5m long in the experimental section. In order to match with the measurement area, the calibration device 100 may be made of 5mm thick transparent acrylic, the inner cavity of the accommodating cavity 110 may be 0.5m (high) × 0.5m (long) × 0.3m (wide), the widths of the first layer cavity 111 and the third layer cavity 113 may be 50mm, the width of the second layer cavity 112 may be 200mm, the inner cavity of the second layer cavity 112 is divided into five sub-cavities 114, and the length of each sub-cavity 114 is 0.1 m.
It can be understood that, since the experimental water level is 0.45m, the water depth in the calibration device 100 may be about 0.4m, and the inner and outer liquid levels of the calibration device 100 are flush. The calibration device 100 needs to be placed on the bottom plate of the water tank, the bottom of the calibration device 100 has a certain thickness, and a gap can be formed between the lower surface of the bottom of the calibration device 100 and the upper surface of the bottom of the water tank by adjusting the adjusting screws on the four mounting holes of the calibration device 100, so that when the calibration device 100 is flush with the liquid level of the water tank, the water depth of the calibration device 100 is slightly lower than the water depth of the water tank. It can be understood that the gap between the calibration device 100 and the bottom surface of the water tank is provided for facilitating the insertion of iron wires to scrape off bubbles attached to the bottom surface of the calibration device, so as to ensure the accuracy of the measured calibration coefficient. In addition, four adjusting screws can adjust the calibration device 100 to keep the calibration device 100 horizontal. After the inner and outer liquid levels of the calibration device 100 are level, the liquid inlet hole 120 can be blocked by a rubber plug, so as to ensure that no liquid exchange exists between the cavities in the calibration device 100.
In this embodiment, rhodamine 6G can be used as the fluorescent substance, and the characteristic concentration thereofc m =0.02ppm. Meanwhile, the concentration of the rhodamine 6G mother liquor adopted in the embodiment can be 1000 ppm. Therefore, the mother liquor of rhodamine 6G to be added into the first layer cavity 111 and the third layer cavity 113 is calculated to be 0.2ml, and the mother liquor of rhodamine 6G to be sequentially added into the five sub-cavities 114 in the second layer cavity 112 is calculated to be 0.064ml, 0.16ml, 0ml, 0.128ml and 0.096ml, and is uniformly stirred.
By adopting the three-dimensional fluid concentration field calibration method provided by the application and combining with 3DLIF equipment to scan and shoot the measurement area once, a group of fluorescence scanning images can be obtained. The scanned image is processed to obtain the non-dimensional laser power linear density distribution and five calibration coefficients, so that the concentration field is accurately calibrated before the concentration field is measured, and the accuracy of the three-dimensional fluid concentration field is improved.
Referring to fig. 4 to 5, based on the same inventive concept, the present application further provides a three-dimensional fluid concentration field calibration method, including:
step S10, determining the positions of a first layer cavity 111, a second layer cavity 112 and a third layer cavity 113 in the calibration device 100 according to the multi-frame scanning image of the calibration device 100;
step S20, determining the positions of at least three sub-cavities 114 in the second layer of cavity 112 according to the scanned image of the second layer of cavity 112;
step S30, determining a first calibration coefficient and a second calibration coefficient according to the average gray value of the positions of the at least three sub-cavities 114 and the corresponding preset concentration of the phosphor solution, wherein the first calibration coefficient is the ratio of the fluorescence concentration to the image gray, and the second calibration coefficient is the initial threshold of the image gray;
step S40, determining a third calibration coefficient according to the image gray scale of the position of the sub-cavity 114 with the maximum preset concentration of the fluorescent substance solution in the at least three sub-cavities 114, wherein the third calibration coefficient is the on-way attenuation characteristic of the laser;
step S50, determining a fourth calibration coefficient and a fifth calibration coefficient according to the scanned image of the first layer cavity 111 and the scanned image of the third layer cavity 113, wherein the fourth calibration coefficient is the fluorescence absorption characteristic of the fluorescent substance solution, and the fifth calibration coefficient is the fluorescence attenuation characteristic in water;
and step S60, converting the scanning image in the measuring process into concentration distribution according to the first calibration coefficient, the second calibration coefficient, the third calibration coefficient, the fourth calibration coefficient and the fifth calibration coefficient, so as to realize calibration of the three-dimensional fluid concentration field. The scanning image in the measuring process is the scanning image obtained in the calibration process of the three-dimensional fluid concentration field by removing the calibration device 100 after five calibration coefficients are obtained for completing the calibration process.
In step S10, image Z-direction positioning may be performed according to the multi-frame scan image of the calibration apparatus 100. First, the multiple frames of scanned images may be sorted and numbered from near to far according to the distance between the plane laser and the lens of the detection device 200. According to the gray average value of the scanned image, the positions of the planar laser passing through the first layer cavity 111, the second layer cavity 112 and the third layer cavity 113 in the calibration device 100 can be determined. In one embodiment, the acquisition speed of the detection device 200 may be 500fps, and the scanning speed of the planar laser may be 1m/s, so that 500 scanning images can be obtained in a single scanning process. The overall gray levels of 500 scanned images are extracted, and the average gray level of each scanned image is calculated. Then, by calculating the difference value of the average gray values of two adjacent scanned images, the gray variation curve of the scanned image can be obtained.
In this embodiment, the position of the initial frame in the Z direction is used as the origin of coordinates, and scanning images of different positions of the probe 200 can be obtained. It can be understood that if multiple sets of scan images are acquired in the calibration process, all scan images at the same spatial position can be averaged. Referring to fig. 4, it can be known from the average gray scale values at different positions that the average gray scale value of the scanned image shows three significant changes when the planar laser passes through the calibration device 100, that is, the structures of the first layer cavity 111, the second layer cavity 112, and the third layer cavity 113 of the calibration device 100 can be reflected, which can be referred to as the average gray scale curve in fig. 4. It will be appreciated that there is a significant drop in mean grey value between two adjacent cavities, since the plane laser light needs to pass through the first partition 20 as it passes from one cavity to the other. By calculating the difference between the average gray values of two adjacent scanned images in the multi-frame scanned image, a change curve of the difference between the average gray values can be obtained, which can be seen in fig. 4. The four extreme points are sequentially found in the gray scale change curve of fig. 4, so that the accurate positions of the first layer cavity 111, the second layer cavity 112 and the third layer cavity 113 can be obtained.
In step S20, please refer to section 2 of fig. 4, after determining the accurate positions of the first layer cavity 111, the second layer cavity 112, and the third layer cavity 113, the scanning image of the second layer cavity 112 is selected, so as to obtain section 2. According to the gray value of the section 2, the positions of at least three sub-cavities 114 in the second layer cavity 112 can be determined, so that a foundation is laid for image processing in the subsequent steps.
In step S30, a concentration gray scale relationship is measured according to the average gray scale values at the positions of the at least three sub-cavities 114 and the corresponding preset concentrations of the phosphor solution. Due to the fact that the water body to be detected contains various impurities or trace chemical components, fluorescence can be causedThe absorption coefficient and the quantum yield of the object are different from the measured value in the purified water, so the field calibration is needed to obtain the real absorption coefficient and the quantum yield in the water body to be measured. In one embodiment, determining the first calibration factor and the second calibration factor according to the average gray scale value at the positions of the at least three sub-cavities 114 and the corresponding preset concentration of the phosphor solution comprises: fitting the mean gray values at the locations of the at least three subcavities 114 to the corresponding preset concentrations of the phosphor solution in the form of
Wherein
Is the average gray value at the location of subcavities 114,
is a preset concentration of the phosphor solution,
in order to obtain the first calibration coefficient,
is the second calibration coefficient.
In this embodiment, the ratio of the fluorescence concentration to the image gray scale and the initial threshold of the image gray scale, that is, the relationship between the fluorescence concentration and the gray scale image, can be obtained according to the scanning image sequence of the second-layer cavity 112. First, the average gray value of the multi-frame scan image sequence of the second layer cavity 112 is calculated to obtain an average image of the second layer cavity 112, and the average image is divided into five partitions (the second layer cavity 112 is divided into five sub-cavities 114 by the second partition 30) by combining with the actual space size of the calibration box 10. In this embodiment, all pixels in the bottom area (not less than one hundred rows) of the five partitions may be extracted, and the average gray value thereof may be calculated, so that the average gray values corresponding to the five cavities may be obtainedG1~G5. Combined with known five chamber concentrationsc1 ~c5By usingLeast square method is used for linear fitting, and the fitting form is
Obtaining the first calibration coefficientC1=aAnd a second calibration factorC2=bWhereinC1AndC2reflecting the relation between the fluorescence concentration and the gray scale of the actually acquired image. Referring also to fig. 6, in one embodiment, the designed concentration ratio in the second cavity 112 may be 0.6: 0.8: 0: 1: 0.4, the concentration proportion can be changed according to actual needs, and the calibration result cannot be influenced after linear fitting is completed.
In step S40, the laser on-way attenuation may be calculated from the image gray scale at the position of the sub-chamber 114 where the preset concentration of the phosphor solution is the largest among the at least three sub-chambers 114. It can be understood that the accuracy of the laser attenuation along the way can be improved by calculating the laser attenuation along the way by using the image gray scale at the position of the sub-cavity 114 with the maximum preset concentration of the fluorescent substance solution in the at least three sub-cavities 114. In one embodiment, determining the third calibration coefficient according to the image gray scale at the position of the sub-chamber 114 with the maximum preset concentration of the phosphor solution in the at least three sub-chambers 114 includes: fitting the mean gray value of each row at the location of the subcavity 114 where the predetermined concentration of the phosphor solution is the highest, in the form of
Then the third calibration coefficient is
，
Is the maximum value of the preset concentration of the phosphor solution. In this embodiment, by averaging the gray scale values of each row at the position of the sub-cavity 114 with the highest preset concentration of the phosphor solution, the gray scale average value on the laser propagation path can be obtained, and fitting is performed by using an exponential function, so that the gray scale average value on the laser propagation path can be obtained
. According to the fitting result, the third calibration coefficient may be
Which reflects the property of fluorescence absorption to cause on-the-way laser decay. In this embodiment, the planar laser may be transmitted along the direction of the column pixels, that is, the optical path of the laser corresponding to each row of pixels is the same, and the average value of each row is obtained from the fluorescence intensity (the inverse of the laser intensity) under the same optical path, so as to obtain the laser intensity signal and the optical path: (xAnd the sum of the optical paths before the laser beam is transmitted into the calibration device), and then fitting to obtain a general rule of attenuation of the laser light intensity along the optical path.
It will be appreciated that the fluorescence light will be attenuated by absorption in the body of water, scattering of trace impurities in the body of water, and absorption of the fluorescence light as it propagates to the detection device 200. Referring to fig. 7, in step S50, the fluorescence attenuation along the path can be measured according to the scanned image of the first layer cavity 111 and the scanned image of the third layer cavity 113. In one embodiment, determining the fourth calibration factor and the fifth calibration factor according to the scanned image of the first layer cavity 111 and the scanned image of the third layer cavity 113 includes: dividing the scanning image of the first layer cavity 111 into a plurality of first areas, dividing the scanning image of the third layer cavity 113 into a plurality of second areas, wherein the first areas and the second areas are in one-to-one correspondence, and the number and the positions of the first areas and the second areas are the same as those of the sub-cavities 114; and calculating the ratio of the average gray value of each first area to the average gray value of the corresponding second area, and determining a fourth calibration coefficient and a fifth calibration coefficient according to the ratio.
In one embodiment, calculating a ratio of the average gray-scale value of each first region to the average gray-scale value of the corresponding second region, and determining a fourth calibration coefficient and a fifth calibration coefficient according to the ratio includes: fitting the ratio of the average gray value of the first region and the average gray value of the second region in the form of
Wherein
Is the ratio of the average gray value of the first region to the corresponding average gray value of the second region,
for the predetermined concentration of the phosphor solution, the fourth calibration factor is
Wherein the length of the second cavity 112 along the distribution direction of the first cavity 111, the second cavity 112, and the third cavity 113, and the fifth calibration coefficient is
Wherein
Is the spacing between the first region and the second region.
It can be understood that, since the fluorescence concentrations in the first layer cavity 111 and the third layer cavity 113 are consistent, if the fluorescence is not attenuated during the propagation process, the gray scales of the scanned images of the section 1 and the section 3 are consistent. In the field calibration, the fluorescence of section 3 is propagated over an increased distance ofsWhile the specific five regions pass through the regions with different concentrations in the second-layer cavity 112, the attenuation degree and the concentration are in a linear relationship. Therefore, by extracting the degree of image gray scale reduction of the cross section 3 with respect to the five regions of the cross section 1 and performing linear fitting, the attenuation speed of the fluorescence propagating in water and the attenuation characteristic by the secondary excitation of the fluorescence depending on the concentration can be obtained.
In this embodiment, five regions corresponding to the five sub-cavities 114 of the second-layer cavity 112 in the cross section 1 and the cross section 3 are extracted, and the average grayscale values thereof are calculated respectively. Wherein, the average values of the gray levels of five regions of the section 1 (closer to the camera lens) are respectivelyA1~A5Cutting offThe average values of the five areas of the surface 3 are respectivelyB1~B5. The sequence is obtained according to the ratio of the corresponding regions of the two sectionsK i ，K i =B i /A i ，i=1~5. To the sequenceK i Andc i performing linear fitting in the form of
A fourth calibration coefficient can be obtainedC4=
And a fifth calibration factorC5=
Whereind 2 The width of the second layer cavity 112 (see the label in figure 7),sthe pitch of the section 1 and the section 3, namely the pitch of the two characteristic sections (refer to the label of fig. 7).C4AndC5reflecting the effect of scattering and absorption of fluorochromes and water during the propagation of fluorescence.
In one embodiment, the three-dimensional fluid concentration field calibration method further includes: after the positions of at least three sub-cavities 114 in the second layer cavity 112 are determined according to the scanning image of the second layer cavity 112, the posture, the moving direction and the moving speed of the detection device 200 are adjusted according to the scanning image of the first layer cavity 111 and the scanning image of the second layer cavity 112; and correcting the multi-frame scanning image of the calibration device 100 according to the scanning image of the first-layer cavity 111. It can be understood that, in the process of measuring the three-dimensional fluid concentration field, the ratio of the scanning speed of the plane laser scanning and detecting device 200 is not completely matched with the refractive index of the water body, so that the scale of the scanned image obtained by the detecting device 200 is related to the spatial position, that is, the spatial accuracy of the measurement result is affected by slight changes between scales at different spatial positions, and therefore, the spatial distortion of the scanned image needs to be corrected.
In one embodiment, adjusting the posture, the moving direction and the moving speed of the detecting device 200 according to the scanned image of the first layer cavity 111 and the scanned image of the second layer cavity 112 includes: performing edge recognition on the scanned image of the first layer cavity 111, and extracting an effective area of the scanned image of the first layer cavity 111; calculating a scanning image scale according to the pixel spacing of the detection device 200 and the size of the calibration device 100; adjusting the posture of the detection device 200 according to the effective area and the scanning image scale; performing convolution cross-correlation processing on the scanned images of the plurality of second-layer cavities 112 to obtain scale variation and image drift; according to the scale variation and the image drift amount, the moving direction and the moving speed of the detection device 200 are adjusted to realize the adjustment of the scanning image shift direction and the shift speed acquired by the detection device 100.
In this embodiment, the effective range in the scanned image of the first layer cavity 111 can be intercepted. Firstly, edge recognition can be performed on a square area with a higher gray value in the cross section 1, the edge of the high-brightness area is extracted, and straight line fitting is performed to obtain a fitting equation of the high-brightness area. In the process of intercepting the effective range, the distance between the pair of vertical parallel lines may be the width of the inner cavity of the calibration device 100, and the distance between the pair of horizontal parallel lines may be a preset or measured water level value. Then, the scale in the horizontal and vertical directions can be calculated according to the pixel pitch of the detection device 200, and whether the acquired scan image has significant image distortion or not can be detected. Meanwhile, the difference between the edges of the two pairs of parallel lines and the horizontal and vertical angles can be further calculated to detect the placement of the detecting device 200, and the posture of the detecting device 200 can be adjusted according to the obtained difference result.
In this embodiment, image distortion measurements may be made from the scanned image of the second layer cavity 112. It will be appreciated that there may be slight variations in the scale of the scanned image as the scanning process progresses. Meanwhile, if the height direction of the calibration device 100 is not parallel to the guide rail of the detection device 200, the laser scanning image will have a certain drift. Thus, by extracting the second baffle 30 position in the fluorescence scan image of the second layer cavity 112, and for different applicationsZThe change in the position of the second diaphragm 30 in the plane is correlated,information on scale change and image drift can be obtained. The scale change is caused by the mismatching of the guide rail running speed ratio and the water refractive index, and the speed ratio of the plane laser to the synchronous scanning of the detection device 200 can be finely adjusted according to the result.
In one embodiment, the correcting the multi-frame scan image of the calibration apparatus 100 according to the scan image of the first layer cavity 111 includes: determining a dimensionless gray value distribution function according to the scanned image of the first layer cavity 111; the multi-frame scanning image of the calibration device 100 is corrected by using a dimensionless gray value distribution function.
It can be understood that since the planar laser used in the actual measurement process is not completely uniform, and the laser is continuously attenuated along with the absorption of the fluorescent object during the propagation process, the intensity of the laser needs to be corrected. In this embodiment, the laser intensity distribution can be calculated from the scanned image of the first layer cavity 111. After the first layer cavity 111, the second layer cavity 112, the third layer cavity 113 and the sub-cavities 114 are positioned, the picture can be cut, rotated and scaled according to the positioning result of the spatial position. And then, carrying out gray extraction and calculation on the scanning image sequence without the instrument installation error to obtain a calibration coefficient group obtained by field calibration. The relative distribution of the laser power density can be obtained by performing gray scale longitudinal extraction on the section 1. The gray values of a plurality of rows (generally not less than 100 rows) at the bottom (laser transmission position) of the section 1 are adopted, the sum of the gray values of each column is respectively solved along the vertical direction, and the distribution function of the gray values and the average value can be obtained
To find out
Can be obtained by calculating the average value of
. Thus, the column gray sums can be dimensionless:
. Obtain laser beam atyAfter distribution, median filtering can be performed on the curve to obtain the linear density distribution of the laser power without quantity (see fig. 4). In the subsequent image processing, the non-dimensional laser power linear density distribution function can be used for correcting the gray scale of any point in the measuring region in the scanned image, namely
Wherein is
For corrected image
The grey value of the location.
It can be understood that the three-dimensional fluid concentration field calibration method provided by the present application may adopt an image processing method matched with the calibration apparatus 100, and the field calibration work of five calibration parameters can be completed at one time through one laser scanning. The calibration parameters comprise an effective measurement space range, laser intensity distribution, a linear relation between the concentration of a fluorescent substance and image gray level, laser and fluorescence on-way attenuation and the like, five calibration coefficients can be output after calculation is completed, a field calibration result file is generated and read in software, and therefore the calibration parameters are directly used for subsequent 3DLIF post-processing work based on a planar light source and a camera synchronous scanning technology, the calibration flow is simplified, and the intelligent level of the 3DLIF calibration process is improved.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be regarded as positions described in the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the patented location. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which belongs to the protection position of the present application. Therefore, the protection position of the application patent should be subject to the appended claims.
Claims (8)
1. A calibration method for a three-dimensional fluid concentration field is characterized in that a calibration device used in the calibration method for the three-dimensional fluid concentration field comprises the following steps:
the calibration box body is surrounded to form an accommodating cavity;
the two first partition plates are arranged in the accommodating cavity and used for dividing the accommodating cavity into a first layer cavity, a second layer cavity and a third layer cavity along the length or width direction of the calibration box body;
the second layer cavity is divided into at least three sub-cavities along a direction perpendicular to the distribution direction of the first layer cavity, the second layer cavity and the third layer cavity; and
the calibration box body is provided with a liquid inlet hole, liquid outside the calibration box body enters the first layer cavity, the second layer cavity, the third layer cavity and the sub-cavities through the liquid inlet hole, the first layer cavity, the second layer cavity, the third layer cavity and the sub-cavities are used for preparing fluorescent substance solution with preset concentration, and the calibration box body, the first partition plate and the second partition plate are made of light-transmitting materials;
the three-dimensional fluid concentration field calibration method comprises the following steps:
installing the calibration device and opening the liquid inlet hole of the calibration device until the inner liquid level of the calibration device is flush with the outer liquid level;
adjusting the positions of the calibration device and the detection device so that the incident plane laser is perpendicular to the distribution direction of the first layer cavity, the second layer cavity and the third layer cavity in the calibration device, and is incident into the calibration device along the height direction of the calibration device, and the detection plane of the detection device is perpendicular to the distribution direction of the first layer cavity, the second layer cavity and the third layer cavity;
preparing the fluorescent substance solution of each cavity in the calibration device according to the preset concentration of the fluorescent substance solution of each cavity in the calibration device and uniformly stirring;
scanning the planar laser along the distribution direction of the first layer cavity, the second layer cavity and the third layer cavity, and acquiring a multi-frame scanning image by using the detection device while scanning, wherein the planar laser and the detection device move synchronously;
determining the positions of the first layer cavity, the second layer cavity and the third layer cavity in the calibration device according to the multi-frame scanning image of the calibration device;
determining the positions of at least three sub-cavities in the second layer of cavity according to the scanning image of the second layer of cavity;
determining a first calibration coefficient and a second calibration coefficient according to the average gray value of the positions of at least three sub-cavities and the corresponding preset concentration of the fluorescent substance solution, wherein the first calibration coefficient is the ratio of the fluorescent concentration to the image gray value, and the second calibration coefficient is the initial threshold of the image gray value;
determining a third calibration coefficient according to the image gray scale of the position of the sub cavity with the maximum preset concentration of the fluorescent substance solution in the at least three sub cavities, wherein the third calibration coefficient is the on-way attenuation characteristic of the laser;
dividing the scanned image of the first layer cavity into a plurality of first areas and dividing the scanned image of the third layer cavity into a plurality of second areas according to the scanned image of the first layer cavity and the scanned image of the third layer cavity, wherein the first areas and the second areas are in one-to-one correspondence, and the number and the positions of the first areas and the second areas are the same as those of the sub-cavities;
calculating the ratio of the average gray value of each first region to the average gray value of the corresponding second region, and comparing the average gray value of the first region with the average gray value of the second regionFitting the ratio of the average gray values of the regions in the form of
Wherein is
The ratio of the average gray-scale value of the first region to the corresponding average gray-scale value of the second region,
for the predetermined concentration of the phosphor solution, the fourth calibration factor is
Wherein
The length of the second layer cavity along the distribution direction of the first layer cavity, the second layer cavity and the third layer cavity is defined as a fifth calibration coefficient
Wherein
Is the spacing between the first region and the second region;
determining a fourth calibration coefficient and a fifth calibration coefficient according to the ratio, wherein the fourth calibration coefficient is the fluorescence absorption characteristic of the fluorescent substance solution, and the fifth calibration coefficient is the fluorescence attenuation characteristic in water;
and converting the scanning image in the measuring process into concentration distribution according to the first calibration coefficient, the second calibration coefficient, the third calibration coefficient, the fourth calibration coefficient and the fifth calibration coefficient so as to realize calibration of the three-dimensional fluid concentration field.
2. The method for calibrating the three-dimensional fluid concentration field according to claim 1, further comprising:
after the positions of at least three sub cavities in the second layer of cavity are determined according to the scanning image of the second layer of cavity, the posture, the moving direction and the moving speed of a detection device are adjusted according to the scanning image of the first layer of cavity and the scanning image of the second layer of cavity;
and correcting the multi-frame scanning image of the calibration device according to the scanning image of the first layer cavity.
3. The method for calibrating the three-dimensional fluid concentration field according to claim 2, wherein the adjusting the posture, the moving direction and the moving speed of the detecting device according to the scanned image of the first layer cavity and the scanned image of the second layer cavity comprises:
performing edge recognition on the scanned image of the first layer cavity, and extracting an effective area of the scanned image of the first layer cavity;
calculating a scanning image scale according to the pixel spacing of the detection device and the size of the calibration device;
adjusting the posture of the detection device according to the effective area and the scanning image scale;
carrying out convolution cross-correlation processing on the scanned images of the plurality of second-layer cavities to obtain scale variation and image drift;
and adjusting the moving direction and the moving speed of the detection device according to the scale variation and the image drift amount so as to realize the adjustment of the scanning image shift direction and the scan image shift speed acquired by the detection device.
4. The method for calibrating the three-dimensional fluid concentration field according to claim 2, wherein the correcting the multi-frame scanning image of the calibration device according to the scanning image of the first-layer cavity comprises:
determining a dimensionless gray value distribution function according to the scanning image of the first layer cavity;
and correcting the multi-frame scanning image of the calibration device by adopting the dimensionless gray value distribution function.
5. The method for calibrating the three-dimensional fluid concentration field according to claim 1, wherein the determining the first calibration coefficient and the second calibration coefficient according to the average gray-scale value at the positions of at least three sub-cavities and the corresponding preset concentration of the phosphor solution comprises:
fitting the average gray value of the positions of at least three sub cavities with the corresponding preset concentration of the fluorescent substance solution in the form of
Wherein
Is the average gray value at the position of the sub-cavity,
is a preset concentration of the phosphor solution,
in order to obtain the first calibration coefficient,
and the second calibration coefficient.
6. The method for calibrating the three-dimensional fluid concentration field according to claim 1, wherein the determining a third calibration coefficient according to the image gray scale at the position of the sub-chamber where the preset concentration of the phosphor solution is the maximum in the at least three sub-chambers comprises:
average gray for each row at the position of the sub-cavity where the preset concentration of the phosphor solution is highestFitting the values in the form of
Then the third calibration coefficient is
，
Is the maximum value of the preset concentration of the phosphor solution.
7. The calibration method according to claim 1, wherein the volumes of the first layer cavity and the third layer cavity of the calibration device are the same, and the lengths of the first layer cavity and the third layer cavity along the distribution direction of the first layer cavity, the second layer cavity and the third layer cavity are the same.
8. The calibration method according to claim 1, wherein the volumes of at least three sub-cavities of the calibration device are the same, and the lengths of the at least three sub-cavities in the direction perpendicular to the distribution direction of the first layer cavity, the second layer cavity and the third layer cavity are the same.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010460551.1A CN111610173B (en) | 2020-05-27 | 2020-05-27 | Three-dimensional fluid concentration field calibration device and calibration method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010460551.1A CN111610173B (en) | 2020-05-27 | 2020-05-27 | Three-dimensional fluid concentration field calibration device and calibration method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111610173A CN111610173A (en) | 2020-09-01 |
| CN111610173B true CN111610173B (en) | 2021-07-27 |
Family
ID=72196106
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010460551.1A Active CN111610173B (en) | 2020-05-27 | 2020-05-27 | Three-dimensional fluid concentration field calibration device and calibration method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111610173B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112285164B (en) * | 2020-10-23 | 2023-01-17 | 天津大学 | Concentration calibration device based on electrical chromatography technology |
| CN113331809B (en) * | 2021-05-20 | 2023-02-14 | 浙江大学 | Method and device for imaging three-dimensional blood flow in cavity based on MEMS micro galvanometer |
Family Cites Families (24)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6749814B1 (en) * | 1999-03-03 | 2004-06-15 | Symyx Technologies, Inc. | Chemical processing microsystems comprising parallel flow microreactors and methods for using same |
| AU2786801A (en) * | 2000-01-10 | 2001-07-24 | Genospectra, Inc. | Linear probe carrier |
| CA2683776A1 (en) * | 2007-04-16 | 2008-10-30 | Orasure Technologies, Inc. | Sample collector |
| CN101718698B (en) * | 2009-11-20 | 2011-08-17 | 宁波基内生物技术有限公司 | Laser-induced fluorescence analyzer with PCR-CE coupled microfluidic chip |
| CN101825564B (en) * | 2010-04-23 | 2012-07-04 | 浙江大学 | Optical detection method for continuously monitoring liquid concentration for a long time |
| CN103063636A (en) * | 2012-12-28 | 2013-04-24 | 江苏大学 | On-line measuring method for mixing concentration field by using planar laser induced fluorescence |
| ES2556143B1 (en) * | 2014-06-10 | 2016-11-14 | Abengoa Solar New Technologies S.A. | Thermal storage system and its loading and unloading procedure |
| CN104133078B (en) * | 2014-07-30 | 2016-08-17 | 清华大学 | Three-dimensional flow field HF measurement system based on sheet photoscanning particle picture and method thereof |
| CN104931466B (en) * | 2014-08-15 | 2017-09-01 | 中国水利水电科学研究院 | PLIF concentration field scaling methods based on column processing |
| CN104535290B (en) * | 2014-12-30 | 2017-10-17 | 黄真理 | A kind of LIF three dimensional fluid detection system and detection method |
| CN204360011U (en) * | 2014-12-30 | 2015-05-27 | 黄真理 | A kind of detection parallel light scanning device |
| CN105987866A (en) * | 2015-02-09 | 2016-10-05 | 中国科学院上海药物研究所 | Heterogeneous liquid settlement automatic-monitoring method and device |
| CN104914078A (en) * | 2015-04-16 | 2015-09-16 | 南京昊控软件技术有限公司 | Large-range multi-point fluid concentration measuring system |
| CN105136058B (en) * | 2015-05-14 | 2018-01-02 | 上海大学 | The on-line proving device and its scaling method of laser sensing three-dimension measuring system |
| CN105973852B (en) * | 2016-03-16 | 2019-01-11 | 上海交通大学 | Fuel jet distribution of concentration test device and its implementation method |
| CN106056587B (en) * | 2016-05-24 | 2018-11-09 | 杭州电子科技大学 | Full view line laser structured light three-dimensional imaging caliberating device and method |
| US10456423B2 (en) * | 2016-06-13 | 2019-10-29 | SMART SURGICAL, Inc. | Compositions for biological systems and methods for preparing and using the same |
| CN106526228B (en) * | 2016-11-02 | 2017-11-07 | 中国人民解放军国防科学技术大学 | The self-calibrating method and system of laser induced fluorescence velocimetry |
| CN106525137A (en) * | 2016-12-07 | 2017-03-22 | 天津大学 | Liquid film temperature field and flow field simultaneous measurement method based on laser induced fluorescence |
| WO2019059961A1 (en) * | 2017-09-25 | 2019-03-28 | California Institute Of Technology | Bistable polynucleotide devices for the sensing and quantification of molecular events |
| CN108120392B (en) * | 2017-11-30 | 2020-03-31 | 东南大学 | Three-dimensional measurement system and method for bubbles in gas-liquid two-phase flow |
| CN109374508B (en) * | 2018-12-06 | 2023-10-10 | 中国科学院武汉岩土力学研究所 | Clogging simulation experiment device and method for tailing drainage system |
| CN109342769B (en) * | 2018-12-10 | 2021-01-12 | 山东省科学院激光研究所 | Calibration method, flow velocity measurement method and device |
| CN110068270B (en) * | 2019-04-18 | 2021-04-02 | 上海拓今智能科技有限公司 | Monocular vision box volume measuring method based on multi-line structured light image recognition |
-
2020
- 2020-05-27 CN CN202010460551.1A patent/CN111610173B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN111610173A (en) | 2020-09-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111610173B (en) | Three-dimensional fluid concentration field calibration device and calibration method | |
| KR0159925B1 (en) | Process for determining the optical quality of flat glasss or flat glass products | |
| CA2411224C (en) | Apparatus and method for non-destructive inspection | |
| JP4901903B2 (en) | 3D inspection system | |
| CN103149560B (en) | Calibrating method for CCD (Charge Coupled Device) imaging lateral laser radar | |
| CN108332708A (en) | Laser leveler automatic checkout system and detection method | |
| CN1158684A (en) | Method and appts. for transforming coordinate systems in an automated video monitor alignment system | |
| Mei et al. | High resolution volumetric dual-camera light-field PIV | |
| CN111784684A (en) | Laser-assisted transparent product internal defect depth setting detection method and device | |
| KR20120006452A (en) | Evaluating method and evaluating device for surface shape | |
| US6996288B2 (en) | Method of calculating shading correction coefficients of imaging systems from non-uniform and unknown calibration standards | |
| US20020089583A1 (en) | Three-dimensional visual inspection method of semiconductor packages and apparatus using single camera | |
| KR20120065948A (en) | Evaluating method and evaluating device for surface shape | |
| CN103245310B (en) | A kind of method adopting X ray reflection instrument to measure sample surfaces characteristic | |
| CN109212546B (en) | Method and device for calculating depth direction measurement error of binocular camera | |
| CN208187381U (en) | Laser leveler automatic checkout system | |
| CN109655415A (en) | A kind of wavelength shift bearing calibration and device and computer equipment | |
| Sveen et al. | A dynamic masking technique for combined measurements of PIV and synthetic schlieren applied to internal gravity waves | |
| RU2474788C1 (en) | Method of measuring tilt angle and wave height of water surface relative equilibrium state thereof | |
| RU2410643C1 (en) | Method to measure angles of inclination and height of water surface roughness relative to its balanced condition | |
| CN114061907A (en) | Halo quantization system and method | |
| EP1400802A1 (en) | Method and arrangement for detecting and evaluating surface irregularities | |
| Emmerich et al. | Ultrasound imaging of liquid fraction in foam | |
| CN109297686B (en) | Method and system for measuring line width of graph and data processing device | |
| CN108020173A (en) | Surface shape measurement apparatus and method based on Structured Illumination |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |